Flathead question

[LSJUNIPER]

Hello,
Was wondering. If you take a stock flathead motor and add headers, aluminum heads and one of the intakes that uses 3 carbs, will this give the motor a good boost in HP??? I have a falthead motor I will be taking to the auto shop for cleaning and testing for cracks. If all is good then I want to rebuild it, but I want to keep it more of an old school build.
Any info will be appriciated...
Thanks

[Vic Piano]

The answer is as easy as yes and no or as they say "as clear as mud". If the engine is in good working order and you install aluminum heads, headers and a multiple carb intake (I would recommend a two pot, not a three) you might see a slight increase in power however, to achieve a "good boost" you'll need to do some additional modifications particularly in the area of ignition. All of the "bolt ons" that you mentioned make excellent “eye candy” on a Flathead but that's about it unless you go all out to build a more powerful Flathead. That's my opinion, I'm sure there will be others.

[LSJUNIPER]

Thanks Vic,
So, boring the block and stroking it may be a way to boost the HP???

[TomT/Williamsburg]

Get JWL's book - goes in to what mods to make, how much they will net you, etc. It really boils down to the fact that no matter how "hot" a flattie you have, it comes down to your trans and gearing, keeping in mind how you want to use/drive the car. My avatar has a 5-speed, 3:54 gears, and 30" tall tires - I can smoke the tires if I want but I built it to drive long distance.

[Tinker]

Good read. link for book

http://www.flatheadv8.org/jwl.htm

[Vic Piano]

Sponsored Links (Register now to hide all advertisements)

Like Tom says, if you want to race it (track engine) or cruise with it (street engine), there are very different modifications that apply to each outcome, final gear ratios and transmission also have an impact. Whatever you decide to do, have fun with it.

[Bassman/NZ]

Investing in JWL's book will allow you to make informed decisions and will save you a lot of money in the long run.

[Ol' Ron]

You can't get a 100 HP from a 239 Flathead by bolting stuff on it, except a blower. Read the Book.

[Tinker]

*****

[4tford]

Tinker, are you Jess??? who sent me paypal for the book???

[Tinker]

Yes Bill. I received your email.

[elwood]

Originally Posted by Ol' Ron

You can't get a 100 HP from a 239 Flathead by bolting stuff on it, except a blower. Read the Book.

^^^^ umm " blower " ^^^^

[Kahuna]

You can't get a 100 HP from a 239 Flathead by bolting stuff on it, except a blower. Read the Book.

I don't believe that for a minute

[usered]

Attached is picture of my '36 LB engine. Pretty much what you were asking about. Alu. heads, two 97's, MSD Ign., what I would call 3/4 race cam, and tube headers. It has a '39 trans and 4:11 gears.

I didn't have it dyno'd (wish I had)but I can sure tell a difference from the stock engine I had before. With the 4:11 gears its not much for touring, If I was going drive it more I'd probably change them. As others above have said it depends on what you want to do.

[Ol' Ron]

John did just about everything you could think of to increase the power of the 239 test engine and only achieved about 95 HP. He then installed a Max#1 cam . the engine then produced aprox. .110 HP along with all the other goodies.. Believe it or not, it's very hard to get 150 HP from one of these engines and still have it street able.

[Charlie ny]

LS,
Cubic inches and compression
Charlie ny

[41LjH]

Others have already said it better than I can. My 239 has been bored 80, Max1, Mallory electronic, Red's headers Isky 424 heads, Isky intake and Holley 390. It sounds great and pulls strong but really does not like to idle. Was in the drive thru line at the bank last week and while everyone was admiring it it stalled! The 39 toploader and 3:78 gear wind it up quick. I believe max torque is under 4000 RPM so I wonder why I did all that!
Determine HOW you are going to drive it, then build it.

[49r]

The best starting point I found was a 4 inch crank.

[gavin m]

I'm no expert so can only go off my personal experience but when I swapped to a set of repro Eddie Meyer heads and matching inlet on my early 21 stud I immediately knocked one and a half seconds from my previous best E.T. in the quarter.
Ran consistent 20.5 secs @72mph to start with then ran 19.001 @78 after the swap, no other changes.
A few more tweaks here and there and I'm now running 17.4 @85mph.

[4t8v8]

Bored .040 over, Max1 cam, Holley 390, Edelbrock heads, headers, flex fan and electronic ignition ( distributor set up by Bubba's). Don't notice much difference in speed, which is ok as I am not a racer. I use it to haul heavy loads in very hilly country. Noticed a big difference there.

[LSJUNIPER]

Thanks for all of the info, looks like I have some home work.

[Ol' Ron]

This would be a good time for the doubters to buy Johns book and follow all the modifications and what worked and what didn't. Here's an interesting fact, On a stock 239 there is no improvement in torque, between the stock single exhaust and duals with headers. But the sound better.

[LSJUNIPER]

Going to order the book today,,,,

[Henry/Kokomo]

In my opinion, if you're contemplating modifying a Ford flathead, two books should be considered required reading. "Nostalgia" by Ron Halloran (sp?) and "Flathead Facts" by John Lawson. I can guarantee you that you'll be money and time ahead to study both works BEFORE you start working on your engine. Flatheads are anything but 'plug and play' machines. Also remember the old addage "There's no replacement for displacement". Good luck with your project!

[hombres ruin]

Originally Posted by usered

Attached is picture of my '36 LB engine. Pretty much what you were asking about. Alu. heads, two 97's, MSD Ign., what I would call 3/4 race cam, and tube headers. It has a '39 trans and 4:11 gears.

I didn't have it dyno'd (wish I had)but I can sure tell a difference from the stock engine I had before. With the 4:11 gears its not much for touring, If I was going drive it more I'd probably change them. As others above have said it depends on what you want to do.

What is that fluid in your spark plug wells on your heads? Is that coolant?

[firerod]

Sponsored Links (Register now to hide all advertisements)

If you have a 239 and add a 4" Merc crank and bore it .040, what is your new cu in?

[BUBBAS IGNITION]

Another good read is here with a cubic inch chart......

http://www.hotrod.com/techarticles/e...e/viewall.html

[V8COOPMAN]

Originally Posted by firerod

If you have a 239 and add a 4" Merc crank and bore it .040, what is your new cu in?

261.8 cu. in. DD

[OLD...BILL]

All the "old school" built engines I was around in the ??good old days?? had a CAM yes a roppen cam, the flathead has to breath, a good cam, big, tall cam will open wider and close the valves faster.... no more than two carbs, or one four barrel, good heads, ie mill the stock heads or add after market heads ?? original dist, built right, and the right coil, stay away from super hot coil, it just not needed.... headers, yes good tube headers, not Fentens, some polish of ports in and out ... ?? WHAT is your ride, an early coupe, you don.t need a big bore.... or a later fordor,heaver sedan go bigger bore, like .80 over plus ?? you don't need a big 11 inch clutch, 9" or 10" max..and yes I agree read the books. good info, and get back to us about gearing, tire size, duel pipes, gauges, and a tacks, oil pressure ?? where and how to make it.?? .... OLD....BILL

[34billct]

Save time and money and go to an SBC

[gkgeiger]

Originally Posted by 34billct

Save time and money and go to an SBC

You're just trying to start trouble, right?

[Ol' Ron]

He could loose his privileges here.

[34billct]

I'm just saying that some people are never happy with the way it was built. I'm vary HAPPY with the power of my stock 34

[Bassman/NZ]

It's in our nature to tinker with things.....

[Flatout]

My stock 59A rebuilt, registered 105 hp on the rebuilders dyno.

[Mike51Merc]

When I got my first flathead I had the idea that I was gonna build a super hot rodded machine. Then I learned a lot, like you're never gonna get 300 horses out of a flattie without a blower and even then you'd be lucky.

It doesn't matter. Flathead is a state of mind.

[Ol' Ron]

could make My dyno say anything, there are calabrating adjustments. Also you need a good weather station.

[Rand]

I like that statement...a lot
It doesn't matter. Flathead is a state of mind.
Randy

[Diavolo]

I would humbly suggest getting Joe Abbin's book as well.

http://www.amazon.com/335-Flathead-F...ords=joe+abbin

He's been building blown and naturally aspirated engines and has proven dyno pulls for each "recipe". The man is an engineer and knows his stuff. You could literally take the book and buy/build according to his proven combinations.

[Fe26]

Originally Posted by LSJUNIPER

Hello,
Was wondering. If you take a stock flathead motor and add headers, aluminum heads and one of the intakes that uses 3 carbs, will this give the motor a good boost in HP??? I have a falthead motor I will be taking to the auto shop for cleaning and testing for cracks. If all is good then I want to rebuild it, but I want to keep it more of an old school build.
Any info will be appriciated...
Thanks

Just wondering which way you decided to go. As the original post was made back in January it's been awhile.

I like the tone of your question, the 'old school' guys (read much younger and without much money way back when) would fit new heads, exhaust and carbs) and yes they did get a modest increase in H.P. But what they really got was 'Street Cred', and louder was always better, right? And shiny, don't get me started on shiney...